First-degree heart block affects the electrical signal that makes the heart beat, causing a slower or abnormal rhythm. There are three degrees of heart block — first-degree heart block does not usually have symptoms or require treatment.
Doctors call heart block atrioventricular (AV) block. It is a type of arrhythmia, or irregular heartbeat.
People may experience AV block that is first, second, or third degree. First-degree heart block is the least serious.
This article discusses what first-degree heart block is. It will also cover the causes, symptoms, treatment options, diagnosis methods, and prevention.
Heart block is a type of arrhythmia, which means irregular or abnormal heartbeat. When someone has heart block, it means their heart can beat slowly or miss beats.
The heart pumps blood around the body and has four chambers. The atria are at the top, and the ventricles are at the bottom.
Typically, electrical signals travel from the atria to the ventricles through a group of cells in between them, called the AV node. It is what makes the heart beat and push blood through the chambers.
When someone has heart block, the electrical signals cannot get through the AV node. This stops the heart from pumping blood as well as it should.
According to the United Kingdom’s National Health Service (NHS), first-degree heart block is the mildest form of the condition. People do not usually notice any symptoms and may not require treatment.
However, it can sometimes progress to second- or third-degree heart block.
In some cases, a person can be born with heart block. This is called congenital heart block.
However, it typically develops as a person ages. This happens when the AV node develops fibrosis, which is the thickening or scarring of the tissue.
It is also more common in males and athletes.
Some risk factors
- having experienced a heart attack
- having heart surgery
- myocarditis, which is the inflammation of the heart muscle
- hyperkalemia, or high potassium levels
- certain medications, such as beta-blockers and calcium channel blockers
Other medical conditions that can cause first-degree heart block
Second- and third-degree heart block
According to the
There are two types of second-degree heart block. The first is called Mobitz type 1. It is less serious and is unlikely to cause symptoms. However, people may feel faint or lightheaded.
The second type of second-degree heart block — Mobitz 2 — is more serious and can lead to:
Third-degree heart block stops the electrical signal altogether. This makes the heartbeat irregular and unreliable, which can lead to serious health problems. Symptoms can include:
- chest pain
- shortness of breath
- extreme tiredness
The symptoms of third-degree heart block can be life threatening and people should seek emergency medical help.
In the majority of cases, people with first-degree heart block do not need treatment. If people are not experiencing symptoms, doctors are likely to monitor a person’s heart to determine if the condition worsens.
For people who experience heart block symptoms or those who have heart block as a result of a heart attack, doctors
To diagnose first-degree heart block, doctors will usually:
- ask the person about their medical history
- carry out a physical exam, including listening to the heart
They will also do an ECG test. This records the heart rate, its rhythm, and the timing of the heart’s electrical signals.
First-degree heart block is not usually serious, and people
If the heart block worsens, complications can include:
- injury as a result of fainting
- low blood pressure
- heart attack
- damage to other internal organs
For people with some congenital heart issues, the causes of heart block are present when they are born. As such, a person cannot always prevent it. However, if a pregnant person has an autoimmune condition, certain treatments can reduce the chance of congenital heart block.
In some cases, there are ways to prevent the causes of heart block. People should focus on maintaining a healthy lifestyle, which includes:
- following a healthy, balanced diet
- avoiding smoking
If people are taking medications, they should discuss the potential side effects and risks with a doctor.
First-degree heart block does not usually interfere with a person’s life. However, people should try to maintain a heart-healthy lifestyle, including exercising and following a balanced diet.
Doctors may recommend that people with pacemakers
Anyone who experiences the symptoms of heart block should speak with a doctor as soon as possible.
Most people with first-degree heart block will not experience symptoms. That is why it is important to have regular health checks.
The AHA recommends people undergo some routine cardiovascular screening tests from the
Heart block is a type of arrhythmia. It means electrical signals in the heart are not working as they should, slowing the heartbeat.
First-degree heart block is the least serious form of the condition. Most people will experience no symptoms and need no treatment.
However, heart block can progress, or worsen. If this happens, doctors may recommend a pacemaker.
People should adopt a heart-healthy diet and lifestyle to help prevent heart block from developing.